(1) Field of the Invention
The invention relates to a method and an apparatus for continuous coating of cores with a dragée-making apparatus including at least one rotatably driven drum in which the product is coated with one or several coating materials or is subjected to other treatment processes, for example spraying, drying and the like.
(2) Description of related Art
In general, the dragée technology differentiates between two different operating modes.
The first operating mode relates to a continuous dragée process, wherein the product to be treated is supplied at the inlet side of a rotating drum and transported toward the outlet side by transport ribs, which are non-rotatably attached to the inner wall of the drum.
The product stream inside the drum is always processed in a single process step, with several process steps performed consecutively. The product is transported continuously through rotation of the drum from the inlet side to the outlet side.
The conventional dragée process advantageously transports the product stream continuously. However, if only small product quantities are to be processed, then this continuous process is expensive and complex. In addition, the charges in a passage through the apparatus are limited.
A second conventional dragée process employees a discontinuous operating mode. A single charge is introduced in a drum and subjected to a specified process flow. The process is performed in relatively small-capacity vessels.
The charge is removed at the end of the process step and introduced into an additional drum for performing the next process step.
Stepwise processing the charge in different, consecutively arranged drums requires complex machinery.
It is known to reduce the throughput times in these conventional batch processes by arranging several drums along the periphery of a circular table and by arranging a number of stationery processing stations opposite the circular table.
The corresponding drum containing the charge is then moved to the respective processing station by rotating the circular table, where the charge is then processed.
At the end of this process step, the circular table is rotated again, and the next drum engages with the associated processing station.
This batch process is complex, in particular, if a large number of process steps are required, because a large number of drums must be arranged on a circular table. However, with this process, even small individual charges can advantageously be processed effectively.
It is therefore an object of the invention to improve the initially described process by providing a process and an apparatus for continuous coating of cores with a dragée apparatus, so that also relatively small individual charges can be processed in a small space using simple machinery.